Internal combustion engine mounting



March 21, 1933. R. K. LEE 1,902,509

INTERNAL COMBUSTION ENGINE MOUNTING Original Filed June 6, 1931 2 Sheets-Sheet l INVENTOR.

I ROGER rr. LEE.

In $32 I? BY g 2 7 ATTORNEYS.

March 21, 1933.1

R. K. LEE

INTERNAL COMBUSTION ENGINE MOUNTING Original File d June 6, 1931' 2 Sheets-Sheet 2 INVEI'VTOR. ROGER LEE.

fi 1 A TTORNEYS.

I Patented Mar. 211, 1933 UNITED STATES PATENT OFFICE noena 1:. man, or HIGHLAND PARK, mcinem, nsslenoa ro onnvsnnn-oonrom TION, or rennan-n PARK, MICHIGAN; A conroanrron or DELAWARE mrnmur. comausrron ENGINE mounrme Original application filed June 8, 1931, Serial No. 542,601. Divided and this application filed February a, 1933. Serial no. 655,129.

This invention relates to an improved internal combustion engine mounting particularly for vehicles, and it is a division of my co-pending application, Serial No. 542,601,

5 filed June 6th, 1931.

10 placement of the center of mass of the unit When an internal combustion engine is yieldably mounted upon a rigid frame structure in such a manner as to permit rocking of the entire engine structure as a unit, discauses reactions upon the rigid frame structure. In a vehicle, thesereactions are directed transversely upon the chassis frame and they are of sufiicient amplitude to de 5 velop excessive vibrations.

A yieldably mounted internal combustion engine is oscillated by the torque reaction impulses which result from the application of the thrusts of the pistons upon a main as the explosions. For this reason, the torque impulses and the oscillations they create vary in frequency in correspondence with the speed at which the engine is operated.

The entire yieldably mounted engine unit, like all other bodies, has a definite and fixed vibration rate, known as the natural vibra-' tion frequency, at which it will vibrate when set in motion. The time 'of each oscillation of such a body is expressed by the formula wherein: T=time, I=moment of inertia, and C represents the resistance resiliently opposing angular displacement of the'body. When the frequency of the torque impulses s chronizes with the natural vibration requency of the engine, severe vibrations are developed. This is also true at the harmonics of the torque period and the natural vibration above formula.

opposing angular displacement of the system driving shaft following the individual ex plosions in the combustion chambers, and whiohoccur in precisely the same frequency.

otal axis of the engine, with respect. to its center of mass, reduces the moment of inertia of the system and tends to reduce the time of each oscillation and to increase thenatural vibration rate of the system, as will be understood from an inspection of the The resistance resiliently may, however, be predetermined to compensate for the reduction of the moment of inertia, so as to prevent synchronizing of the torque impulses with the natural vibration frequency in the driving range of the engine.

The main object of the invention is to 'provide in a motor vehicle, an internal combustion engine mounting of such character as to prevent excessive vibration of the motor vehicle due to the operation of the en ine. With this end in view, leading objects 0 the invention are to provide a mounting for a power plant unit including an internal combustion engine which, While permitting oscil- I lation' of the unit under the influence of the torque reaction impulses, will prevent substantial displacement of the center of mass thereof during such oscillation; to provide a mounting of this character which maintains the moment of inertia that opposes oscillation of the engine unit at a low value so as to obviate the application of transversely directed reaction thrusts upon a vehicle chassis, or on the, rigid frame structure by which the unit is supported; to provide yieldable members for independently supporting the weight of the engine unit which also permit oscillation of the said unit about the approximately proper axis; and to provide resilient means cooperating predetermining t e natural vibration frequency of the units.

In general, the invention consists in p20- viding, u on the motor vehicle frame, mount-- ing mem rs for the power plant unit, in-

cluding an internal combustion engine, which members shall be of such character and so located as to provide an axis of oscillation passing substantially through the center of mass of the power plant unit, and permit oscillation of the unit about such axis. Thus, the torque reaction impulses will be dissipated with the mounting for engine crank shaft, although not necessarily in the vertical plane thereof, the invention contemplates the provisions. of mounting members for the power plant unit of such character and solocated as to provide an axis of oscillation for said unit extending at an angle to the crank shaft axis and passing through the center of mass of the unit. In other words, the invention contemplates mounting the power plant unit upon members which permit an oscillatory movement of the unit about an axis passing through the cen ter of mass. The invention consists, further, in utilizing resilient members, preferably non-metallic, such as rubber, as the means for providing the axis of oscillation, whereby the weight of the power plant unit is yieldably supported and transversereactions upon the chassis frame are obviated; The invention also consists in providingzmounting ele ments of such character and so located as to provide an axis of oscillation for the unit passing substantially through the center of the connections, at the front end of the main shaft, through which power *is transmitted to said shaft, as well as through the center of mass of the power plant unit. The invention also consists in providing means which resiliently oppose angular displacement of the power plant unit about the axis of oscillation provided by the mounting members. uch means will be so selected as to predetermine the resistance resiliently opposing angular displacement, so that the natural vibration frequency of the system, determined as statedby the formula 1 frequency of the unit will not synchronize with the frequency of the torque impulses within the drlving range of the engine. The resistance resiliently opposing angular displacement of the unit may be furnished, in part at least, by the members which provide the axis of oscillation, but may be supple mented by additional means furnishing such resistance.

Lwaao'e Fig. 3 is a fragmentary transverse section taken on the line III-III of Fig. 1.

Fig. 4 is a transverse vertical section taken on the line IV-IV of Fig. 1. e i

Fig. 5 is a transverse section, similar to Fig. 3, of amounting and internal combustion engine assembly, illustrating a further embodiment of the invention.

In the form shown, my improved internal combustion engine mounting is illustrated in conjunction with a .vehicle chassis frame which includes side channel members 1, between which extend rigid transverse front and rear structures 2 and 3 respectively,

The front transverse structure 2 is rigidly secured at its ends to the side channel members 1 by rivets 4: and the rear transverse structure, 3 is rigidly secured to these side members by rivets 5.

Located between the side members 1 and the transverse structures 2 and 3 is a power plant unit including a multiple cylinder in- I ternal combustion engine 6 having a crank shaft "7, which extends longitudinally of they chassis frame, and pistons and connecting rods (not shown) which operate in planes that are normal to the axis of the crank shaft. A rigid support 8 of triangular shape is fixed to the front transverse structure 2-by bolts 9, or other suitable means. The top of the sup port 8 is located substantially at the upper extremity of the crankcase 10 of the engine slightly below a forwardly protruding flange 11 which is integrally formed on the upper V end of the crankcase.

The front end of the engine is tiltably supported on the upper extremity of the support 8 by a rubber block 12 which is disposed between an inner metal bracket 13 and an outer metal bracket 14. The rubber block 12 is rigidly fixed independently to the brackets 13 and 14: which are secured to the support 8 and flange 11 by bolts 15 and 16, respectively.

The brackets 13 and 14 are preferably bonded by vulcanization to the oppositesides of the block 12.

The rear end of the engine 6 is tiltably mounted on the rear transverse structure 3 of the chassis frame by an arcuate shaped rubber element 17 which is confined within a channel 18 of an arcuate shaped bracket 1-9 that is rigidl fixed by bolts 20 on a flange 21 protruding rom the rear end of the transmission housing 22 of the engine. The rubber element 17 is rigidly secured to the bracket 19, preferably by vulcanization, and it is rigidly attached in a similar manner to an.

I end of the support 8, about which the front end portion of the engine is tiltable, and the rubber element 17 tiltably supports the rear end of the engine, the so-called axis locating point formed by the rear yieldable supporting structure being located substantially at the center of curvature of the arcuate brackets 19 and 23. Since the rubber elements 12 and 17 are of substantial width, they provide, in reality, relatively short axes, the mid-points of which are considered'the main axis locating points, above mentioned. These are designated by the numerals 24 and 25, respectively, provided by the front and rear supporting structures, and are located in alignment with each other and substantially with the center of mass of the engine, designated by the numeral 26. This alignment of the axis locating points with the center of mass of the engine causes oscillation of the latter to occur about an axis, illustrated by the line 27, which extends substantially-through the center of mass, 26. The rubber elements 12 and 17, therefore, permit oscillatory move ment of the engine about said axis of oscillation. It should be noted that the upper end of the support 8, which carries the rubber cushion 12, is not directly above the crank shaft 7, but is slightly offset laterally, as shown in Fig. 2. By such positioning ofthe member 12, the axis of oscillation is so located as to pass through the center of mass of the power plantunit, although, due to un-.

symmetrical distribution of mass, such center of mass is not situated in the vertical plane passing through the crank shaft axis. It will be noted, by reference to Figs. 1 and 4, that the rear axis locating point 25 is located substantially at the center of the universal joint at the rear end of the transmission 22, customarily employed to connect the power plant with the main shaft 7 Conventional internal combustion engines of the type used in motor vehicles have their mass asymmetrically distributed with respect to the crank shaft, and therefore the center of mass of the engine is generally lo-' and upwardly from the region at which.

power is transmitted from the engine .to an external member, such as the main drive shaft 7 of the vehicle.

Since the axis of oscillation passes substantially through the center of mass of the engine, the center of mass is not displaced during oscillation of the en ine in response to thetorque reaction inipu ses. By avoiding displacement ofthe center of mass of the engine incident to theoscillatory movement of the latter in dissipating the torque reaction impulses, the latter are not sudden- "ly opposed, and therefore the. application of violent transversely directed thrusts upon I the chassis frame is prevented. These torque reaction impulses are gradually dissipated during oscillation of the engine through asubstantial arcuate distance, but they are not suddenly opposed by a moment of large value which exists when the center of mass of the engine is located at a substantial distance from the axis of oscillation.

In a mounting of this kind which permits the oscillatory movement of the power plant unit about an axis that extends through the center of mass of the entire system, the

moment of inertia of the system with respect to its axis is reduced to a low value. This reduction in the moment of inertia tends to increase the natural vibration frequency of the system to such an extent that such frequency would, without proper precaution, synchronize with the frequency. of the torque reaction impulses during the driving range of operation of theengine. This condition is highly undesirable, for when the torque impulses are in phase, or in harmonic relation with the natural vibration rate, severe vibration is created in the frame and body structure of the vehicle.

q The natural vibration rate of the engine is maintained low enough so that the frequency of the torque reaction during the driving stage of the engine will not synchronze with the natural vibration characteristics of the engine. In theform shown, the natural vibration frequency of the engine is definitely established at a sufficiently low rate by mount--- ing the engine upon the rubber blocks 12 and" 17, which not only provide the axis of oscillation, but afford some resistance resiliently opposing angular displacement of the engine, and independently retarding angular displacement'by apparatus which coacts between the engine and the frame of the vehicle resiliently opposing angular displacement of 'the engine. The angular displacement resisting apparatus includes a flexible leaf spring 28 which is fixed at its rigid end to the lower side of the clutch housing 29- of the engine by a bracket 30. The flexible end of the leaf spring 28 is received in a slot 31. formed in a rubber block 32 which is fixed on the lower side of the channel member 1 'of the frame,

as shown in Fig. 3. The leaf spring 28 bends freely when the engine is urged a counter-clockwise direction about its axis of oscillation by the reaction of the torque impulses, and it controls the natural Vibration frequency of the system so as to avoid syn- 5 chronizing of the latter with the frequency of the torque reactions during the. driving range.

tion frequency'of the system with the freuency of the torque impulses during the rivingrangeof the'engine is'avoided. As a result, the ap .ication of shock and vibration upon the chassis frame by operation of the engine is materiall reduced during driving at a constant spee as well as during deceleration and acceleration of the vehicle.

The yieldable elements 12 and 17 support the main weight of the engine and freely fperinit oscillation thereof abouttlie axis 0 oscillation which extends lengthwise of the engine and with respect to which a low moment of inertia is present, but .they are of such character. and so'located as toxresist oscilla-' 'tion'of the unit about a transverse axis under 'theinfluence ofreciprocation of the pistons. In Fig.5 is shown a mounting and internal combustion engine assembly similar to that v I illustrated-in Figs. 1 to 4, inclusive, and having corresponding parts designated by the Y numerals used in the description of the latter figures. The structure illustrated inv'Fi 5 includes, in addition to that presenteif in Figs. 1 to 4, a stop 33 which is mounted'on the right side of the rear transverse structure 3, and which has a yieldable; pad 34, preferablycomprising rubber, on its inner extremity. The pad 34 registers with an upright vertical flange 35 on the transmission housp ing 22 of the engine assembly, which is normally held against the pad with an initial compression by the spring 28 of the angular displacement resisting apparatus when the engine is not operating, and when the torque reaction impulses are of insufiicient magnitude to rotate the system in a counter-clock- ;wise direction. as viewed inFig. 5, against the action of the spring 28. When the torque reaction impulses-are of suflicient magnitude to rotate the flange 35 out of engagement with: the pad 34,the actions described in-the discussion of Fi 1 to 4, inclusive, occur in the manner set orth above,

It is to be understood that this invention is concerned with the oscillatory movement of to permit the engine to oscillate throug its the engine and all parts so attached thereto so as to oscillate as a unit'therewithand that,

whenever I have referred to the engine, engine umt, power plant unit, or mternal combustion engine .as'sembly7, I mean 130 include all'parts which are mounted on the engine proper, so as to oscillate as a unit therewith. While I have herein shown and described an engine which includes a transmission, it will be readily understood that such transmission may be omitted or separately mounted, such as construction merely changing the center of mass of the engine and requirin relocation of the engine sup orts new center of mass. 7

Although but several specific embodiments of this invention have herein been shown and described, it will be understood that various 1 changes in the size, shape and arrangement of parts may be made without departing from. the spirit of my invention, and it is not my intention to limit its scope other than'by the terms of the appended claims,,--- a What I claim is: i 1. The comb nation of an internal combustion engine unit having a crankshaft, supporting structure, and means for mounting said unit on said supporting structure so constructed and arranged ans-to mount saidam gine unit for oscillation about anaxis extending substantially through .the center of mass of sa d engine unit and the axis'of said cranks'h 1 4 12. In a vehicle includi g a chassis'frame and a main drive shaft, the combination of an internal combustion engine unit having 'a' crankshaft connected with said m'ain' dr ve shaft and a plurality of cylinders distributed longitudinally of the engine shaft, and means on said frame supporting said engine unit 0 and so constructed and arranged that the axis of oscillation of the engne unit substantially coincides with an axisextending forwardly from within close proximity to the forwardend of said main drive shaft substantially through the center of'mass of said engine unit.- 1 1 3. The comb nation of a frame, apower plant unit including an internal combustion engine and a crankshaft, the center of mass of said unit being located above the axis of the crankshaft, and a mounting for said unit comprising a plurality of members carried by .t e frame and engaged by said un t, said members being of such character and so lo-- htl an linclinationto cated as to provide for oscillation of said unit on an axis extending at an angle to the crank-' shaft axis and passing substantially through the center of mass of said unit and to permit oscillation of the unit about sa d axis of oscillation. I r

4. The combination of a frame, a power, plant unit including an internal combustion engine having a' plurality of cylinders dis-1 I ioo tributed longitudinally of the engine shaft, and a mounting for said unit comprising a lurality of resilient memberscarried by the rame and engaged by said unit, said -members being of such character and so located that the axis of oscillation of said unit passes substantially through the center of mass thereof and the unit is permitted a limited oscillation about such axis.

5. The. combination of a frame,'a power plant unit including an internal combust on engine having a plurality of cylinders distributed longitudinally of the egine shaft, and a mounting for said .unit comprising a plurality of members carried by the frame and engaged by said unit, said members be ing of such character and so located that the axis of oscillation of said unit passes substantially through the center of mass thereof and the unit is permitted a limited oscillation about such axis, at least one of said mem-' bers being resilient.

6. The combination of a frame, a power plant unit including an internal combustion engine having a crankshaft, the weight of the unit being asymmetrically distributed relative to the crankshaft, and a mounting for said unit comprising a plurality of non-metallic, resilient members carried by saidframe and engaged by said unit, said members being of such character and so located that the ax s of oscillation of said unit passes substantially through the center of'mass thereof and the unit is permitted resiliently resisted oscillation about such axis.

7. In a vehicle including a chassis frame and a main drive shaft, the combination of a transmission and an internal combustion engine having the crankshaft connected with said main drive shaft through the transmission, and means on said frame including rubber members mounting said engine un t and ,so constructed and arranged as to provide for oscillation about an axis extending substantially through the center of mass thereof so as 'to permit oscillation of said engine about said axis under the influence .of the torquesecured to said frame and secured to said unit,

said elements being so formed and located jbustionengine unit having a crankshaft the as to provide for oscillation of the un t about an axis passing substantially through the center of mass thereof. 7

9. The combination of a frame, a power plant unit including an internal combustion engine having a crankshaft, the said engine being asymmetrically distributed relative to the crankshaft, and a mounting for said unit for said unit comprising a including a plurality-of rubber members carried by said, frame and engaged by said unit, said members bein so formed and located as to determine an provide an axis of oscillation for said unit passing substantially through the center of mass thereof and permit oscillation of the unit about such axis.

10. The combination of an internal combustion engine unit havin a crankshaft, and with its mass asymmetrica 1y distributed with respect to the crankshaft, a frame structure and yieldable members coacting between said frame structure and said engine unit to mount the latter and being so constructed and arranged as to provide for oscillationthereof about a single axis extending substantially through the center of mass of said unit at an inclination to the'crankshaft axis.

11. The combination of an internal combustion engine unit having a crankshaft, and with its mass asynmietrically distributed with respect to the crankshaft, a frame structure,

and means including yieldable members fixed independently to said frame structure and engine unit, respectively, so constructed and plant unit including an internal combustion engine and a crankshaft, the center of mass of said unit being located above the axis of the crankshaft, and a mounting for said unit comprising a plurality of rubber elements carried by said frame and engaged by said unit, said elements being so formed and lo-- 1 cated as to mount said unit for oscillation about an axis extending at an angle to the crankshaft axis and passing substantially through the center of mass of said unit.

13. The combination of a frame, a power plant unit including an internal combustion engine havin a plurality of cylinders distributed longitudinally of the engine shaft, a mounting for said unit comprising a plurality' of members carried by the frame and engaged by said unit, said members being of such character and so located as to provide an axis of oscillation for said unit passing substantially through the center of mass thereof and permit oscillation of the unit about such axis, and means resiliently opposing angular displacement of the unit about saidaxis,

14. The combination of an internal comweight of the unit being asymmetrically distributed relative to the crankshaft, a supporting structure, and members coacting between said structure and unit to support the latter and so constructed and arranged that the axis of oscillatoryv movement of the engine unit substantially coincides with an axis engine unit.

15. The combination of a supporting structure, a, power .plant unit including an internal combustion enginehaving a plurality of cyliinders distributed longitudinally of the enextending through the center of mass of the gine shaft, 'and'a plurality-of members interposed between said supporting structure and thevcrankshaft, a mounting for said unit comprising a lurality of members carried by the frame an engaged by said unit, said members being of such character and so located as toprovide an axis of oscillation for said unit extending at an angle to the crankshaft axis and passing substantially through the center of mass of said unit, and means resiliently opposing angular displacement of the unitabout said axis.

17. The combination of a frame, a power plant unit including an internal combustion, f. enginehavmg a crankshaft, the saidengine being asymmetrically distributed relative to the crankshaft, amounting for said unit comprising a plurality of non-metallic resilient members carried by the frame and engaged bg :said unit, .said' members being of such. c a

meter and so located as to mount said unit for oscillation about an axis passing substantially through the center of mass thereof, and means independent of said members for resiliently opposing such oscillation.

18;. The combination of a frame, a power plant unit including an internal combustion engine and a'crankshaft, the center of mass.-

of said unit being located above the axis of the crankshaft, amountingfor said unit comp r1s1ng a plurality of rubber elements carried by the frame and engaged by said unit,

said elements being. of such character and so located that the 'axisof oscillation of said umt extends at an angle to the crankshaft 20. The combination of a supporting structure, an internal combustion engine unit and cushion mounting members carried by the support and engaged by the unit, said members being spaced longitudinally of the shaft and of such character and so located as to provide for resiliently opposed vertical and transverse movement of the unit as well as oscillation of the unit on an axis passing substantially through the center of mass of the unit.

'21. In combination, an internal combustion engine unit having a crankshaft, fore andaft cushion mounting means for the unit, spaced longitudinally of: said-crankshaft, and positioned at diflferent vertical heights, one mounting means being above" the .said'crankshaft and the other mounting means being at a lower position, said mountings 'being so. constructed and arranged as to provide for oscillation of said engine on an axis inclined to the crankshaft substantially intersecting one end of the the said crankshaft axis at unit.

22. In'combination, an internal combustion engine unit having a crankshaft, fore and aft cushion mounting meansfor the unit, spaced longitudinally of said crankshaft, the forward mounting means being positioned above the said crankshaft and the rearward mounting means being at a lower position,

said mountings being soconstructed andjarranged 'as'to provide for oscillation of said axis at one end. of ,the umt.

23. In combination, an internal -combus engine on an axis inclined to the crankshaft. su stantially intersecting the said crankshaft crankshaft, said axis being abovethe crankshaft at one end thereof and said mountings being located entirely within the long1tu 1- nal vertical side planes of the engine.

ROGERK. LEE.

axis and passes substantiall through the center of mass of said unit, an means resilientl opposmg angular displacement of the umt about such axis.

of said unit being located above the axis of 19. The 'combination'of a frame, a power plant unit including .aninternal combustion engine and a crankshaft, the center of mass the crankshaft, and a mounting for said unit comprising-a plurality of members carried, by the frame and engaged by said unit, said members being'of such character and so 10- cated that the axis of oscillation for said of mass of said unit.

unit passes substantially through the center 

